<!--
 * @Author: your name
 * @Date: 2021-08-13 16:40:09
 * @LastEditTime: 2021-08-16 15:07:55
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: /day04-网易严选/css/middle.html
-->
<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>居中显示</title>
  <style>
    .outer {
      width: 500px;
      height: 500px;
      background-color: aqua;
      position: relative;
    }

    .inner {
      width: 200px;
      height: 200px;
      background-color: beige;
      position: absolute;
      margin: auto;
      top: 0;
      bottom: 0;
      left: 0;
      right: 0;
    }
  </style>
</head>

<body>
  <div class="outer">
    <div class="inner">

    </div>
  </div>
</body>

</html>